060
FXUS10 KWNH 220702
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
301 AM EDT FRI MAY 22 2020
VALID MAY 22/0000 UTC THRU MAY 25/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..CUT-OFF LOW IMPACTING THE OH VALLEY AND NORTHERN MID-ATLANTIC
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND
CONFIDENCE: ABOVE AVERAGE
OVERALL, THE GLOBAL MODELS ARE IN VERY GOOD AGREEMENT WITH THE
DETAILS OF THE CUT-OFF UPPER LOW DRIFTING NORTH NOW OVER THE OH
VALLEY WHICH SHOULD TURN EAST ACROSS THE NORTHERN MID-ATLANTIC
REGION BY SATURDAY AND THEN HEAD OFFSHORE. THE 00Z NAM RATHER
EARLY IN THE PERIOD BECOMES SLOWER THAN ALL OF THE GLOBAL MODELS
IN ADVANCING THE SYSTEM EASTWARD. WILL PREFER A NON-NAM BLEND
SINCE THE GLOBAL MODELS ARE TIGHTLY CLUSTERED IN AGREEMENT.
..DEEP UPPER TROUGH/CLOSED LOW RELOADING OVER THE WESTERN U.S
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THE LATEST GUIDANCE SHOWS VERY GOOD AGREEMENT IN BRINGING A NEW
LARGE SCALE UPPER TROUGH AND ASSOCIATED CLOSED LOW IN ACROSS THE
PACIFIC NORTHWEST AND THROUGH THE INTERMOUNTAIN WEST BY THIS
WEEKEND. BY EARLY NEXT MONDAY, THE CONSENSUS OF GUIDANCE SUPPORTS
A DEEP TROUGH EDGING TOWARD THE PLAINS WITH A CLOSED LOW CENTER
MOST LIKELY OVER THE CENTRAL ROCKIES. MODEL MASS FIELDS ARE IN
GOOD AGREEMENT OVERALL, BUT BY THE END OF THE PERIOD, THE 00Z GFS
AND 00Z ECMWF BOTH TEND TO FOCUS THEIR CLOSED LOW A LITTLE NORTH
OF THE 00Z NAM, 00Z UKMET AND 00Z CMC. THE UKMET IN PARTICULAR
MADE A NOTABLE SOUTHWARD SHIFT FROM ITS PREVIOUS RUN. THE 00Z GEFS
MEAN AND YESTERDAY'S 12Z ECENS MEAN BOTH TEND TO SUPPORT THE
FARTHER SOUTH CONSENSUS. HOWEVER, SINCE THE GFS/ECMWF SOLUTIONS
ARE NOT OUTSIDE THE FULL ENSEMBLE SPREAD, THEY ARE PLAUSIBLE
SOLUTIONS. SO, BASED ON THIS, A GENERAL MODEL BLEND WILL BE
PREFERRED FOR THE PERIOD.
..SHORTWAVE LIFTING NORTHEAST ACROSS THE MIDWEST BY LATE FRIDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND
CONFIDENCE: ABOVE AVERAGE
AHEAD OF THE DEEP LAYER TROUGHING OVER THE WESTERN U.S., THE
MODELS ALLOW A SHORTWAVE TROUGH TO LIFT NORTHEAST FROM THE
SOUTHERN HIGH PLAINS AND ACROSS THE MIDWEST BY LATE FRIDAY. THE
GUIDANCE FAVORS SOME AMPLIFICATION OF THIS SYSTEM WITH A CLOSED
MID-LEVEL LOW CENTER FORMING FRIDAY NIGHT OVER EASTERN NE AND THEN
LIFTING THROUGH THE UPPER MIDWEST ON SATURDAY. THE ENERGY WILL
THEN BEGIN TO WEAKEN OVER THE GREAT LAKES BY SUNDAY AS IT ATTEMPTS
TO CREST THE DEEP LAYER RIDGE FORMING AND NOSING NORTHWARD BY THEN
OVER THE OH/TN VALLEYS AND SOUTHEAST. OVERALL, THE 00Z NAM IS
STILL SEEN AS BEING A TAD SLOWER AND DEEPER THAN THE GLOBAL MODELS
WITH THIS ENERGY. THE GLOBAL MODELS WITH THE 00Z CYCLE ARE NOW
VERY WELL CLUSTERED WITH THEIR TIMING AND DEPTH, SO A NON-NAM
BLEND WILL NOW BE PREFERRED WITH THIS SYSTEM.
..SHORTWAVE LIFTING NORTHEAST ACROSS THE SOUTHERN PLAINS SUNDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-UKMET BLEND
CONFIDENCE: AVERAGE
AS THE DEEP TROUGH AND ASSOCIATED CLOSED LOW EVOLVES ACROSS THE
WEST THIS WEEKEND AND SLOWLY ENCROACHES ON THE HIGH PLAINS, THERE
WILL BE A SHORTWAVE TROUGH ROUNDING THE BASE OF IT AND LIFTING
NORTHEAST ACROSS THE SOUTHERN PLAINS ON SUNDAY. THE 00Z UKMET IS A
TAD STRONGER THAN THE REMAINING GUIDANCE WITH ITS ENERGY PIVOTING
ACROSS CENTRAL AND EASTERN TX, AND ACTUALLY SUGGESTS A
CONVECTIVELY INDUCED MID-LEVEL LOW CENTER FORMING OVER
SOUTH-CENTRAL TX BY THE END OF THE PERIOD. THE REMAINING GUIDANCE
IS AT LEAST A BIT MORE SUBTLE WITH THIS IDEA, AND SO A NON-UKMET
BLEND WILL BE PREFERRED WITH THIS SHORTWAVE ENERGY CONCENTRATING
ACROSS CENTRAL AND EASTERN TX.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
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